TORONTO - An anesthesiologist is suggesting recommendations on how to perform cardiopulmonary resuscitation or CPR may need to be changed.

Dr. Anthony Ho says that when CPR guidelines were updated in 2010 a step that is probably needed was taken out.

The international experts who revised the guidelines in 2010 dropped the recommendation that people alternate chest compressions with mouth-to-mouth resuscitation.

They said the idea of breathing into someone's mouth might discourage some people from attempting CPR and the breaths took time away from the more important chest compressions.

But Ho says the 2010 guidelines also dropped a recommendation to tilt back the head and lift the chin of the unconscious person and he thinks that was a mistake.

The Queen's University professor says studies should be done to see if tilting the head and lifting the chin increase survival rates of people on whom CPR is performed.

"My argument is I think they threw the baby out with the bath water," says Ho, who is also an anesthesiologist at Kingston General Hospital in Kingston, Ont.

Writing in the Canadian Medical Association Journal, Ho says tilting the head and lifting the chin helps to open the airway, which is critical so that the chest compressions can expel and draw air into the lungs.

The key responsibility of anesthesiologists is to ensure that people who are unconscious still get the oxygen they need to survive. As such, people in the profession spend a lot of time studying the best way to maintain open airways.

The 2010 revision of the CPR guidance by the International Liaison Committee on Resuscitation — known as ILCOR — drew a lot of attention because of the decision to drop the recommendation for what is known as rescue breathing. One of the hopes was that more people would attempt to do CPR on people who suffer cardiac arrest because of the change.

But that wasn't why the change was made. Studies had been done that showed CPR without rescue breathing was actually more effective than CPR that alternated chest compressions with rescue breathing. The studies showed that with rescue breaths, about 12 per cent of people lived; without them, the number went up to 14 per cent.

"An increment of two per cent means many, many people (survive) worldwide, because cardiac arrest is quite common," Ho says.

Dr. Andrew Travers, an emergency physician at the Halifax Infirmary, is co-chair of the basic life support task force for ILCOR, an umbrella organization for national organizations around the world that advocate for and train people to conduct CPR. In Canada, that group is the Heart and Stroke Foundation.

Travers says the 2010 update that Ho is questioning was aimed at people who are untrained in CPR technique. Rescue breathing is still recommended for trained emergency responders.

Travers says the decision was based on the fact that the chest compressions are the most important part of the effort, and should be what an untrained individual focuses on when performing CPR. Doing that well is not easy, he says.

Cardiac arrest often happens at home, where perhaps only one other person is present. Under those circumstances, calling 911 and then focusing on chest compressions is the best thing a person can do, Travers says.

"If there are more people there, then yes, you can do more of these things. But if you're by yourself, and most cardiac arrests are ... then we're asking you to do is: OK, just push hard and push fast."

"If you can do these other things, then great. But don't sacrifice that basic foundation piece of CPR," he insists.

Ho agrees that chest compressions are the most important part of CPR. But he says if resuscitation is being attempted by two people, one person could hold the head with the chin up to facilitate air flow.

"My argument is perhaps we can make even further gains, if we can just tweak the technique a little bit."

He acknowledges at this point his idea is a hypothesis that needs to be studied, but says it fits with what is known about airway maintenance.

"It is a proposal that sounds logical, sounds physiological and seems to be better. And it is an idea that needs to be investigated before it will be put into practice, if indeed it proves to be correct," he says.